In a watermarking process the original data is marked with ownership information (watermarking signal) hidden in the original signal. The watermarking signal can be extracted by detection mechanisms and decoded. A widely used watermarking technology is spread spectrum coding. See, e.g., D. Kirovski, H. S. Malvar, “Spread spectrum watermarking of audio signals” IEEE Transactions On Signal Processing, special issue on Data Hiding (2002), incorporated herein by reference in its entirety.